ACTION OF HYDROGEN 115 



After dealing with the tendency of hydrogen combined 

 with carbon to be replaced by metals, we may take hydro- 

 gen combined with oxygen, i. e. hydroxyl. Here, in accord- 

 ance with the facility metals have for combination with 

 carbon the tendency to metallic combination is far more 

 marked. This tendency, however, to form ' metallic alco- 

 holates ' is in a high degree dependent on the hydrogen 

 otherwise contained in the compound, and diminishes with 

 increase of the latter. Taking the extreme cases phenol 

 and hexyl alcohol 



C S H 8 OH, C H ]3 OH, 



the predominance of acid character in phenol is marked by 

 the name ' carbolic acid/ Actually potassium phenolate, 

 C 6 H 5 OK, can be prepared from potash like a salt according 

 to the equation 



C 6 H 5 OH + KOH = C H 5 OK + H 2 O, 

 whereas for hexyl alcohol, potassium is needed 



This again is connected with the fact that the metallic 

 derivatives in question are hydrolytically dissociated by 

 water, in the first case slightly, in the second strongly, and 

 that the constant governing the equilibrium 



XOK + H 2 O ^ XOH+ KOH 



is here to be regarded as a measure of the influence of 

 hydrogen. For potassium phenolate this can be numerically 

 determined l by measuring the velocity with which methyl 

 acetate is saponified in solution with the phenolate, as this 

 allows of calculating directly the amount of potash. It 

 was found that : 



0-0962 normal solution at 24*1 was 3-05 / o hydrolyzed, 

 0-0195 24-1 6.69% 



whilst hexyl alcohol was hydrolyzed to the extent of more 



than 90 / o . 



1 Shields, Zeitschr. f. Phys. Chemie, 12. 175. 

 H 3 



